The present invention relates to a new and improved method of monitoring the mold geometry during the continuous casting of steel billets and blooms.
It is already known to the art to increase the withdrawal of heat by conically tapering at all sides the hollow mold compartment in the lengthwise direction of the cast strand at continuous casting molds for the continuous casting of billets and blooms. In this way it is also possible to favorably affect the growth of the strand shell or skin. There are different teachings as to the manner in which there is to be accommodated the taper to the strand contraction, in order to obtain the positive effect as concerns the heat removal and the strand skin growth without there being present too great mold friction. However, a once optimized mold geometry changes during the course of the use of the mold due to wear and/or distortion in such a manner that, for instance, there is eliminated the predetermined mold taper or, in fact, there arises a converse taper. When there prevails inadequate geometry of the mold then there can arise damage to the cast strand, for instance, fissures or metal break-out.
It is equally known to the art that the carbon content of unalloyed steels tends to extremely variably influence the heat withdrawal and the mold friction. Thus, the carbon content is also taken into account during optimizing the mold taper.
In order to avoid damage it is therefore conventional practice in this art to check the mold geometry from time-to-time by means of a suitable gauge or the like when the mold is not in use. However, for this purpose there must be undertaken complicated and time-consuming measurements with the aid of micrometers or electronic gauges or the like at the continuous casting mold during such time as the same is not in use, i.e. during pauses between the casting operations.